ESTRO course on Image Guided Radiotherapy in Clinical Practice 2018

Observer variation in the neck

Prevertebral Level 1-2

 18 observers – MCA, AvL, VUMC, ARTI, RISO, MST, MCH, UMCG, RIF, MAASTRO, UMCN, DDHK, UMCU, Leuven, Middelheim,  1 patient  Delineation according to guidelines as published by Gregoire et al – R&O 2003

Gregoire et al 2003 R&O

2 top

2 mid

Overall observer variation (SD)

2 bottom

GTV CT GTV CT MRI

Lymph nodes

Anatomical regions

SD CT (mm)

SD CT (mm)

SD CT (mm)

All regions

3.6

4.4

3.3

4.4

3.4

2.7

Anterior

3.7

3.6

2.7

Dorsal

4.6

7.7

3.5

Caudal

3.8

Cranial

3.0

L-R

4.0

Parotid

2.2

Vertebrae

2.3

Vessels

2